SAN FRANCISCO — Tesla is starting to build its electric cars with all the sensors, cameras and other gear needed to drive completely on their own when regulations allow the technology to take over that responsibility.

The announcement made late Wednesday by Tesla CEO Elon Musk marks the Silicon Valley automaker’s next step toward selling cars that can navigate the roads without the help of a human.

Google, ride-hailing service Uber and an assortment of other automakers also are working on a range of self-driving cars.

Tesla has offered an automatic steering and braking system called Autopilot in its cars since last year, but that technology is meant to be monitored at all times by a driver.

After additional testing and getting the necessary regulatory clearance, all the cars rolling off Tesla’s assembly lines will have the equipment needed to be fully autonomous, Musk said. By auto-industry standards Tesla is small, making about 100,000 cars a year, although it hopes to increase production to 500,000 vehicles by 2018.

Musk predicted the technology will be twice as safe as a human driver. But adding the protection will jack up prices on Tesla vehicles that already can run over $80,000 depending on what features a buyer wants. Adding the software and activating the hardware needed for a fully autonomous car will cost an additional $8,000 — a more than 20 percent increase on the cost of Tesla’s $35,000 Model 3 sedan that is scheduled to be delivered next year.